Great Midweight Puffy that's Lightweight
I love this jacket. It's very warm and very light. It compresses down small and lofts up huge. The down is firm in each baffle; it feels like it's stuffed full, almost squishy. With a base layer in this jacket, you will be warm sitting around camp well into the teens or lower.
Its biggest competitor, the Feathered Friends Hooded Helios, has the same amount of down but weighs 4-5 oz. less. However, for those extra few ounces in this jacket, you get more durable fabric, water resistant zippers, velcro adjustments in the hood and wrists, zippered hand warmer pockets instead of elastic, full waist adjustments with drawcord instead of elastic, drop tail that covers your butt to make you warmer, a fully adjustable hood with wire brim and velcro stays instead of just one adjustment, plus a hood that covers more of your face and provides more insulation. Depending on your application, this makes the Rab Neutrino a more well rounded and fully-featured jacket. And also the reasons why I chose it over the Hooded Helios.
For fit, I'm 5'10" and 200lbs with an athletic frame (33" waist, 44" chest, 35" arms, wide shoulders), and the large fits me perfectly. I have just enough room to put a couple more layers without compressing the down. The jacket also completely covers my butt, which is really nice when you're at a cold belay.
For weight, it's advertised at 22oz, but my size large weighs exactly 21 ounces. The stuff sack it comes with weighs .75 oz., in case you care.
Hard not to recommend this jacket. Great for pretty much anything outside of the greater ranges.